Background:Nucleotide repeat expansion disorders constitute a group of clinically and genetically heterogeneous diseases, pathologically characterized by the misfolding, aggregation, and accumulation of proteins. The expanded GGC repeats in the 5' untranslated region (5'UTR) of the NOTCH2NLC gene translate into uN2CpolyG, a toxic polyglycine protein that leads to neuronal intranuclear inclusion disease (NIID). However, the precise composition of uN2CpolyG and its pathogenic mechanisms remain fully unclear. Objectives:We aimed to investigate the proteomic profile of uN2CpolyG and explore the novel neuropathology in NIID patients, which may underlie the disease pathogenesis. Methods:Mass spectrometry analysis was performed on purified intranuclear inclusions to investigate the proteomic profile. Three patients with genetically confirmed NIID were enrolled; two participants underwent skin biopsy, and one underwent brain autopsy. Skin and brain tissues derived from these patients were used to examine NOTCH2NLC-related pathological changes. Results:A group of enriched proteins interacting with uN2CpolyG were identified, characterized by significant intrinsically disordered regions (IDRs). Among these, we detected the co-localization of uN2CpolyG with PML and FUS in notably distinct patterns, causing significant DNA damage and impaired stress response. Furthermore, FUS- and PML-positive inclusions were confirmed in NIID patients' tissues. Conclusion:Our findings provide novel insights into the proteomic profile and neuropathology of NIID, potentially enlightening the pathogenesis and therapeutic strategies for protein aggregation-related neurodegenerative diseases.

Objective·To analyze the clinical, imaging, and genetic characteristics of spastic paraplegia (SPG) phenotypes caused by amyotrophic lateral sclerosis (ALS)-related genes.Methods·A total of 5 pedigrees with SPG caused by ALS-related genes, admitted to the Department of Neurology, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University School of Medicine, from April 2017 to September 2025, were included in the study. Detailed medical histories and imaging examinations were collected, and Sanger sequencing, family co-segregation verification, and phenotype analyses were performed.Results·Among the 5 probands, the male-to-female ratio was 3:2. The average age at onset was (18.4±21.7) years (ranging from 1 to 51 years), and the average disease duration was (12.8±13.3) years (ranging from 3 to 33 years). Physical examination revealed increased muscle tone in the lower extremities in all patients (5/5), hyperreflexia in the lower extremities (5/5), patellar clonus in 2 patients (2/5), ankle clonus in 4 patients (4/5), positive pathological signs in the lower extremities in 4 patients (4/5), and foot deformities in 2 patients (2/5). Brain MRI examinations detected abnormalities in 2 patients, specifically cerebellar and cervical spinal cord atrophy in case 1, and a small number of abnormal signals in the splenium of the corpus callosum in case 2. Peripheral nerve electrophysiological examinations indicated that a small number of spontaneous potentials were observed in both lower extremities of 1 patient, and motor evoked potentials revealed central conduction impairment. Genetic testing identified pathogenic variants in 4 different genes, namely amyotrophic lateral sclerosis 2 (ALS2), valosin-containing protein (VCP), senataxin (SETX), and never in mitosis gene A-related kinase 1 (NEK1), in these 5 patients. Among them, 2 new variants, c.3527T>C (p.Met1176Thr) and c.1732T>C (p.Ser578Pro), were newly discovered in the ALS2 gene.Conclusion·This article analyzes the clinical heterogeneity and genetic characteristics of SPG patients caused by ALS-related genes, providing clinical evidence for accurate diagnosis and in-depth understanding of such diseases.

Central demyelinating disorders, notably myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), exhibit diverse clinical and radiological manifestations, thereby complicating accurate diagnosis. We present the case of a 78-year-old female patient who developed progressively worsening bilateral lower limb numbness and weakness, accompanied by fecal incontinence over a two-month period. Spinal MRI identified a longitudinally extensive lesion within the spinal cord, and serological analysis revealed MOG antibodies at a titer of 1:100. The patient experienced partial clinical improvement following glucocorticoid treatment, with no further neurological decline. Nevertheless, subsequent spinal magnetic resonance angiography uncovered a spinal arteriovenous malformation. This case underscores the potential diagnostic overlap between demyelinating and vascular myelopathies and highlights that partial responsiveness to steroids and the presence of specific antibodies do not preclude concurrent vascular pathology. Therefore, comprehensive diagnostic assessment, including vascular imaging, is warranted in patients exhibiting atypical or progressive myelopathy despite evidence suggestive of immune-mediated disease. These observations emphasize the clinical heterogeneity inherent to central demyelinating disorders and contribute valuable insights into the neuroimmunological and diagnostic challenges associated with such conditions.

Background and purposeParaneoplastic neurological syndromes (PNS) is an uncommon disorder affecting the central nervous system (CNS), peripheral nervous system, or autonomic nervous system. The aim of this study was to analyze the clinical characteristics of anti-amphiphysin-IgG-positive autoimmune syndrome and to assess its association with a spectrum of​ anti-amphiphysin-IgG-associated autoimmune syndromes and tumors.MethodsWe reported clinical data of four patients with anti-amphiphysin-IgG-positive autoimmune syndrome, and conducted a literature review.ResultFour amphiphysin-IgG-positive cases were identified. Within our cohort, antibodies feature was comprised of isolated amphiphysin-IgG (2/4), coexisting aquaporin-4-immunoglobulin G (AQP4-IgG) (1/4), coexisting N-methyl- D -aspartate receptor immunoglobulin G (NMDAR-IgG) (1/4). Clinical presentation included conus medullaris-cauda equina syndrome (1/4), myelitis (2/4) and stiff-person syndrome (SPS) (1/4). The coexisting cancer was involved of lung cancer (1/4).ConclusionAnti-amphiphysin-IgG-positive autoimmune syndrome demonstrate heterogeneous clinical presentations, including myelitis, SPS, and rare variants like conus medullaris-cauda equina syndrome. Coexistence with other neural antibodies (e.g., AQP4-IgG or NMDAR-IgG) may elevate tumor risk. While strongly associated with malignancies such as breast and small cell lung cancer (SCLC), combined immunotherapy and oncologic therapy can stabilize or improve neurological function in subsets of patients. Early serologic testing and sustained cancer surveillance are imperative for prompt intervention and prognostic optimization.

Leukoencephalopathy with ataxia (LKPAT), also known as CLCN2-related leukoencephalopathy, is a rare autosomal recessive disorder caused by pathogenic variants in CLCN2, which encodes ClC-2, a ubiquitously expressed chloride channel protein. However, due to high variability in clinical presentation leading to underdiagnosis, very few cases have been reported since its first description in 2013. The prevalence and genotype-phenotype correlations of LKPAT remain unclear, as do the pathogenic mechanisms of CLCN2 variants. In this study, we reported a Chinese man who presented with dizziness, weakness of the left lower limb, and mild cerebellar ataxia. Notably, the patient had a history of azoospermia. Brain MRI showed symmetrical and confluent white matter abnormalities with hypointense signals on T1-weighted images and hyperintense signals on T2-weighted images. In this patient, a novel biallelic missense variant p.A506V was identified in CLCN2. Through in silico analysis, we observed that substitution of A506 with V506 altered hydrogen bond formation at chloride-binding sites. In addition, the A506V variant impacted the interaction of ClC-2 with GlialCAM, a ClC-2 auxiliary subunit that can physically bind ClC-2 and regulate its biophysical properties and subcellular localization in glial cells. Furthermore, we reviewed the literature and identified potential genotype-phenotype correlations in CLCN2-related diseases. Our results highlight the need for CLCN2 genetic analysis to establish a definitive diagnosis when strong diagnostic clues are present. This study expands the genotypic spectrum of LKPAT, indicates the potential pathogenesis of the CLCN2 A506V variant, and provides valuable insights into further investigation into therapeutics of CLCN2-related leukoencephalopathy.

Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by progressive cognitive decline. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have shown neuroprotective potential, but the mechanisms underlying these effects remain incompletely understood. This study investigated whether semaglutide, a long-acting GLP-1RA, ameliorates AD-like phenotypes in APP/PS1 mice and explored associated changes in neuroinflammatory signaling and blood–brain barrier (BBB) integrity. Eight-month-old amyloid precursor protein/presenilin 1 (APP/PS1) transgenic mice were treated with semaglutide for 8 weeks. Cognitive performance was evaluated using the Morris water maze (MWM). AD-related neuropathology, neuroinflammation-associated protein markers, BBB integrity–related measures, and microglial ultrastructure were assessed using histological, ultrastructural, and molecular approaches. Fecal microbiota composition was profiled by 16 S rRNA amplicon sequencing. Semaglutide improved cognitive performance in APP/PS1 mice and was associated with attenuation of neuronal loss–related changes, reduced Aβ deposition, and improved synaptic ultrastructure. Semaglutide also reduced the AD-associated upregulation of inflammasome-/pyroptosis-associated proteins (including NLRP3-related and caspase-11–related markers) and TLR4/NF-κB–related inflammatory signaling proteins, accompanied by attenuation of microglial mitochondrial ultrastructural abnormalities. In addition, semaglutide improved markers of BBB integrity (tight junction proteins and brain albumin levels) and increased BBB-related Aβ clearance proteins (LRP-1 and P-gp). Gut microbiota profiling revealed genus-level differences between WT and APP/PS1 mice without significant changes in α- or β-diversity. Semaglutide was associated with improved cognition and attenuation of AD-like pathology and neuroinflammatory signaling in APP/PS1 mice, accompanied by partial preservation of BBB integrity.

Parkinson's disease (PD) is characterized by Lewy body pathology, mainly consisting of accumulation of aggregated α-synuclein and lipid contents. Lipid dyshomeostasis has frequently been observed in PD, and compelling evidences indicate that lipids play critical roles in modulating α-synuclein toxicity. However, how α-synuclein regulates brain lipid composition remains poorly understood. Here, we used dual polarity matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) to spatially profile brain lipids in a unilateral adeno-associated virus (AAV)-α-synuclein mouse model of Parkinsonism. We identified region-specific alterations in sphingolipids and glycerophospholipids in the substantia nigra and striatum of these mice. In sphingolipids, α-synuclein overexpression altered certain monosialotetrahexosylgangliosides (GM1s), sphingomyelins (SMs), and sulfated hexosyl ceramides (SHexCers; a.k.a. sulfatides). Glycerophospholipid changes followed a desaturation pattern: polyunsaturated fatty acid (PUFA)-containing species were decreased, while saturated and mono-unsaturated species were increased. Additionally, oxidized phosphatidylcholine (PC) lipids, such as SAzPC (1-stearoyl-2-azelaoyl-sn-PC) and PAzPC(1-palmitoyl-2-azelaoyl-sn-PC), were elevated in the substantia nigra, and ether phosphatidylethanolamines (PEs) were reduced in the substantia nigra but increased in the striatum. Our study provides a comprehensive, spatially resolved lipidomic landscape of α-synuclein-induced pathology in the nigrostriatal pathway, offering new insights into lipid dysregulation in experimental PD and a framework for future therapeutic exploration.

AIMS:N6-methyladenosine (m6A) facilitates functional recovery following ischemic stroke (IS). This study investigated the role of Sptbn2 in post-stroke cognitive impairment (PSCI) and the mechanisms regarding m6A. METHODS:HT-22 cell damage and ferroptosis were analyzed following OGD exposure. pMCAO surgery was performed to establish an IS mouse model. We assessed neurological deficits and cognitive impairment in mice using the mNSS, adhesive removal test, rotarod test, novel object recognition test, and Y-maze test. Adeno-associated viral vectors with overexpression of Sptbn2 combined with pMCAO surgery were used to analyze cognitive dysfunction and ferroptosis. RESULTS:Sptbn2 was reduced in neurons of PSCI mice. Sptbn2 overexpression alleviated ferroptosis-induced neuronal damage by promoting the membrane translocation of Slc7a11. Hnrnpa2b1 promoted Sptbn2 stability through an m6A-related mechanism. Knockdown of Sptbn2 reversed the mitigation of ferroptosis by Hnrnpa2b1 and exacerbated the neuronal injury. Under OGD, Bard1 knockdown reduced the Hnrnpa2b1 ubiquitination, slowed Hnrnpa2b1 degradation, and restored Sptbn2 expression. Knockdown of Bard1 alleviated neuronal ferroptosis, thereby reducing the development of cognitive impairment in mice, a phenotype reversed by Hnrnpa2b1 or Sptbn2 knockdown. CONCLUSION:In IS, Bard1-associated regulation of Hnrnpa2b1 ubiquitination is accompanied by reduced Sptbn2 expression and impaired Slc7a11 membrane translocation, and is involved in neuronal ferroptosis-related damage.

Intranuclear inclusions are defining features of many neurodegenerative diseases, yet their assembly mechanisms and pathological roles remain poorly understood. Here, we investigate polyglycine (polyG) inclusions in neuronal intranuclear inclusion disease (NIID) and show that they recruit intrinsically disordered proteins to form stratified, immobile condensates that disrupt nuclear protein quality control and DNA damage repair. Leveraging their ordered and stepwise assembly, we identify promyelocytic leukaemia protein (PML) as a key factor that actively recognizes and eliminates polyG inclusions through chaperone-mediated disaggregation and proteasome-dependent degradation. Engineered PML variants selectively clear both nuclear and cytoplasmic aggregates, including polyG, polyGA, polyQ, TDP-43 and SOD1. Systemic PML delivery alleviates cognitive and motor deficits in mouse models of NIID and TDP-43 proteinopathy. These findings uncover a conserved spatial organization of nuclear inclusions and establish PML as a therapeutic effector for neurodegenerative diseases linked to protein aggregation.

Objective To report 2 cases of Charcot-Marie-Tooth disease type 4H (CMT4H) caused by FGD4 gene variation and review the relevant literatures, summarizing the clinical and gene mutation characteristics of CMT4H. Methods and Results Two families with CMT4H diagnosed by genetic test in Shanghai Sixth People's Hospital Affiliated to Shanghai Jiaotong University School of Medicine from May 2020 to July 2022 were included. The probands in 2 families were both sporadic patients with onset in early adolescence, manifesting as progressive postural gait abnormalities, difficulty walking, and foot deformities. Nerve electrophysiological examination showed multiple demyelinating damages to sensory and motor nerves. Sural nerve biopsy in proband of family 1 disclosed a decreased density of myelin fibers and demyelinating neuropathy with thickened and excessively folded myelin sheath. Whole exome sequencing (WES) revealed that both probands had compound heterozygous mutations in the FGD4 gene, all of which were novel, and cosegregated with the family members. Conclusions CMT4H is a peripheral neuropathy mainly caused by autosomal recessive demyelination, and case report from 2 families further expand the spectrum of FGD4 gene mutations.

PURPOSE:We aim to summarize the clinical and genetic features of five patients with KIF5A variants and explore genotype-phenotype correlations alongside a functional analysis of these mutations. METHODS:Detailed clinical data of five unrelated SPG10 patients were collected, including clinical symptoms, family history, physical examinations, brain and spinal MRI, electrophysiological examinations, etc. KIF5A variants were identified by whole exome sequencing, followed by Sanger sequencing, family co-segregation, and phenotypic reevaluation. Moreover, we also performed functional studies of each identified variant. RESULTS:All five probands were male, among whom one presented with pure form, and the other four with complicated form, including sensory ataxia, cognitive impairment, and peripheral neuropathy. Five heterozygous KIF5A mutations were identified, including c.446-2A > G, c.593T > C (p.Met198Thr), c.611G > A (p.Arg204Gln), c.614G > A (p.Ser205Asn), and c.838C > T (p.Arg280Cys). Among these, c.446-2A > G and c.614G > A (p.Ser205Asn) were newly reported. In vitro, c.446-2A > G destroyed the original donor site, leading to either 8bp deletion upstream of Exon6 (c.446_453del, p.V149Dfs∗20) or Exon 6 skipping (c.446_501del, p.V149Gfs∗4), thus generating two various truncated mutant forms with 167 and 151 amino acids, respectively. The two mutants had less molecular weight and reduced protein expression level, which also lost colocalization with α-tubulin. Another four missense mutations, with normal mRNA and protein expression levels, lost colocalization with α-tubulin in subcellular location. CONCLUSION:We identified five KIF5A mutations with different phenotypes: the classic SPG symptoms with foot deformity, and complicated phenotype with sensory ataxia or peripheral neuropathy. Furthermore, we proved that KIF5A haploinsufficiency and abnormal subcellular location are associated with SPG10.

Background and purpose: Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive cognitive dysfunction, which is common in the elderly. In recent years, it has been reported that glucagon-like peptide 1 (GLP-1) analogues have neuroprotective function. However, the mechanism of GLP-1 analogues improving neurological function has not been fully clarified. This study attempts to clarify the mechanism of GLP-1 alleviating AD phenotype. Methods: In this study, a modified once-weekly GLP-1 analogue, Semaglutide, was used to treat 8-month-old amyloid precursor protein / presenilin 1 (APP/PS1) transgenic mice. By means of ethology, molecular biology and 16s rRNA amplicon sequencing, it was confirmed that Semaglutide alleviated the disease phenotype of APP/PS1 mice. Results: GLP-1 improved the behavioral performance of APP/PS1 mice, reduced neuronal damage and aggregation of amyloid-β (Aβ) plaques, and enhanced synaptic plasticity. GLP-1 also attenuated pyroptosis mediated by NOD-like receptor thermal protein domain associated protein 3 (NLRP3), inflammatory reaction mediated by toll-like receptor 4 (TLR4) and mitochondrial damage of microglia as well as improved the structure and function of blood-brain barrier (BBB) in AD mice. Conclusion: GLP-1 may repair the blood-brain barrier to alleviate the central nervous system injury caused by the displacement of pyrogen in gut of AD mice.

IntroductionHereditary diffuse leukoencephalopathy with spheroids (HDLS), caused by CSF1R mutations, is a rare autosomal dominant leukodystrophy characterized by rapid neurological decline. Hematopoietic stem cell transplantation (HSCT) is a promising treatment, but the risk of post-transplant complications such as invasive fungal disease (IFD) remains underexplored. Microglial dysfunction in CSF1R-related disorder (CRD) may further impair host immune defense.MethodsWe describe a Chinese male with a non-hotspot CSF1R mutation (c.2443-1G>C) who underwent allogeneic HSCT. A multidisciplinary team (MDT), including clinical pharmacists, implemented an individualized pharmacological strategy for antifungal management, guided by immune status, infection risk, pharmacokinetics, and next-generation pathogen diagnostics.ResultsDespite prophylaxis with voriconazole and levofloxacin, the patient developed febrile neutropenia and otitis media by day +16. Empirical meropenem therapy was ineffective, prompting escalation to teicoplanin and caspofungin. Pulmonary infection developed; targeted sequencing of bronchoalveolar lavage identified Aspergillus flavus. Antifungal therapy was intensified with voriconazole, resulting in clinical resolution by day +70. Treatment was maintained with good response.DiscussionThis case demonstrates the complexity of managing IFD in CSF1R-related disorder patients after HSCT. The interplay between systemic immunosuppression and intrinsic microglial dysfunction may heighten infection susceptibility. Precision antifungal therapy guided by multidisciplinary team expertise and pharmacological monitoring may improve outcomes in this rare and high-risk population.

Colony-stimulating factor 1 receptor (CSF1R) is primarily expressed in microglia. Its monoallelic mutation causes CSF1R-associated microgliopathy (CAMP), a major form of adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) and a fatal neurological disease without clinical cure. We developed mouse models harboring human hotspot mutations of CAMP and replaced CSF1R-deficient microglia with CSF1R-normal cells through microglia replacement by bone marrow transplantation (Mr BMT), which attenuated pathology in mice. We further demonstrated that, in the context of CSF1R deficiency, traditional bone marrow transplantation (tBMT) in ALSP functions similarly to Mr BMT, efficiently replacing microglia and reducing disease progression. We then replaced CSF1R-deficient microglia in eight patients by tBMT. The disease progression was halted during the 24-month follow-up. Together, microglia replacement corrects pathogenic mutations and halts disease progression in mice and humans.

HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a progressive neurological disorder with limited treatment options. We report a 54-year-old female with decade-long, progressive HAM/TSP, previously refractory to rituximab, who experienced worsening spastic paraparesis and neurogenic bladder dysfunction. She showed remarkable improvement in spasticity, bladder function, and quality of life following combination therapy with efgartigimod and corticosteroids. This case highlights efgartigimod's potential as an adjunctive therapy for refractory HAM/TSP, suggesting a new immune modulation strategy and warranting further research into combination treatments.

Objective Hereditary transthyretin amyloidosis (ATTRv) is an autosomal dominant genetic disease characterized by the misfolding and deposition of the transthyretin (TTR) protein. This study aimed to describe the clinical and genetic characteristics of ATTRv in a large multicenter Chinese cohort. Methods Patients from 14 centers were included in the study. The clinical and genetic characteristics of all patients were summarized. The peripheral blood white blood cell mitochondrial DNA (mtDNA) was detected in offspring from different genders. Results A total of 202 individuals with ATTRv from 148 families were identified. The average age of onset was 50.6 ± 12.4 years. Among these cases, 117 (57.9%) were classified as late‐onset (≥50 years) and 85 (42.1%) as early‐onset. Overall, the length dependent axonal sensorimotor peripheral neuropathy was the predominant phenotype (89.1%). A total of 42 heterozygous missense variants and 1 deletion variant were identified. The most common variants were Val30Met (19.8%) and Ala97Ser (15.8%) and patients with Val30Met and Ala97Ser were mostly late‐onset in our cohort. Thirty‐nine of these patients died with a mean age of 56.1 ± 13.5 years. Anticipation according to gender groups of offspring‐parent pairs was different, and mother‐son pairs showed the largest anticipation. The copies of mtDNA in the mother's offspring outnumbered those of the father's offspring ( p < 0.001). Interpretation This study highlights that ATTRv patients in China exhibit high heterogeneity in their initial symptoms. The most common variants observed in this cohort is Val30Met. The mtDNA copy number shows gender‐linked effects. These results can impact ATTRv diagnosis and patient care strategies. ANN NEUROL 2025

Macrophages in the brain barrier system include microglia in the brain parenchyma, border-associated macrophages at the brain's borders, and recruited macrophages. They are responsible for neural development, maintenance of homeostasis, and orchestrating immune responses. With the rapid exploitation and development of new technologies, there is a deeper understanding of macrophages in the brain barrier system. Here we review the origin, development, important molecules, and functions of macrophages, mainly focusing on microglia and border-associated macrophages. We also highlight some advances in single-cell sequencing and significant cell markers. We anticipate that more advanced methods will emerge to study resident and recruited macrophages in the future, opening new horizons for neuroimmunology and related peripheral immune fields.